Hybrid automatic repeat request (H-ARQ) and cell selection are linking techniques employed by 1xEV-DV forward link services on the shared Forward Packet Data channel (FPDCH) between cells and mobile stations (MS). Cells comprise base transceiver stations (BTS) in wireless environments which have lower traffic and sectors, which subtend an angular portion of a full periphery such as 120°, having applications in wireless environments which have higher traffic.
For a reverse link soft handoff from one cell to another cell, in a CDMA system, the communication path is maintained during cell switching, without disrupting the original communication path (make before break transfer). Reverse link soft handoff has problems with redundant channel elements and Abis interface (the interface overhead between the base station controller (BSC) and the cells) which significantly affects cell performance.
H-ARQ has been applied to the Supplemental Channel on the reverse link to improve throughput. H-ARQ uses multiple instances of an acknowledgment-based stop-and-wait ARQ protocol for code combining.
Cell selection is a handoff technique that allows the MS to identify an optimal cell (base station to base station, base station to sector or sector to sector) based on a mobile assisted handoff technique (MAHO) measurement. The MS uses the carrier signal strength to interference ratio (C/I) measurements to select the best cell for forward link transmission and indicates to the members of the active set. See L. Jalloul, “Joint 1XTREME proposal for 1XEVDV”, 3GPP2-C50-20001 204-006R1, Kauai Hi., December 2000 with further details being set forth in Faisal Shad, “1XTREME Uplink Hybrid ARQ Procedures”, 1XTREME MAC Ad-Hoc, March 2000.